mei: expose fw version to sysfs

The ME FW version is constantly used by detection and update tools.
To improve the reliability and simplify these tools provide
a sysfs interface to access version of the platform ME firmware
in the following format:
<platform>:<major>.<minor>.<milestone>.<build>.
There can be up to three such blocks for different FW components.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

4 files changed, 144 insertions, 8 deletions

diff --git a/Documentation/ABI/testing/sysfs-class-mei b/Documentation/ABI/testing/sysfs-class-mei
index 81ff6abf9673..17d7444a2397 100644
--- a/Documentation/ABI/testing/sysfs-class-mei
+++ b/Documentation/ABI/testing/sysfs-class-mei
@@ -54,3 +54,14 @@ Description:	Configure tx queue limit
 
                 Set maximal number of pending writes
                 per opened session.
+
+What:           /sys/class/mei/meiN/fw_ver
+Date:           May 2018
+KernelVersion:  4.18
+Contact:        Tomas Winkler <tomas.winkler@intel.com>
+Description:    Display the ME firmware version.
+
+                The version of the platform ME firmware is in format:
+                <platform>:<major>.<minor>.<milestone>.<build_no>.
+                There can be up to three such blocks for different
+                FW components.
diff --git a/drivers/misc/mei/bus-fixup.c b/drivers/misc/mei/bus-fixup.c
index b17c46a43812..e45fe826d87d 100644
--- a/drivers/misc/mei/bus-fixup.c
+++ b/drivers/misc/mei/bus-fixup.c
@@ -1,7 +1,7 @@
 /*
  *
  * Intel Management Engine Interface (Intel MEI) Linux driver
- * Copyright (c) 2003-2013, Intel Corporation.
+ * Copyright (c) 2003-2018, Intel Corporation.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -96,8 +96,22 @@ struct mkhi_fwcaps {
         u8 data[0];
 } __packed;
 
+struct mkhi_fw_ver_block {
+        u16 minor;
+        u8 major;
+        u8 platform;
+        u16 buildno;
+        u16 hotfix;
+} __packed;
+
+struct mkhi_fw_ver {
+        struct mkhi_fw_ver_block ver[MEI_MAX_FW_VER_BLOCKS];
+} __packed;
+
 #define MKHI_FWCAPS_GROUP_ID 0x3
 #define MKHI_FWCAPS_SET_OS_VER_APP_RULE_CMD 6
+#define MKHI_GEN_GROUP_ID 0xFF
+#define MKHI_GEN_GET_FW_VERSION_CMD 0x2
 struct mkhi_msg_hdr {
         u8  group_id;
         u8  command;
@@ -139,21 +153,81 @@ static int mei_osver(struct mei_cl_device *cldev)
         return __mei_cl_send(cldev->cl, buf, size, mode);
 }
 
+#define MKHI_FWVER_BUF_LEN (sizeof(struct mkhi_msg_hdr) + \
+                            sizeof(struct mkhi_fw_ver))
+#define MKHI_FWVER_LEN(__num) (sizeof(struct mkhi_msg_hdr) + \
+                               sizeof(struct mkhi_fw_ver_block) * (__num))
+#define MKHI_RCV_TIMEOUT 500 /* receive timeout in msec */
+static int mei_fwver(struct mei_cl_device *cldev)
+{
+        char buf[MKHI_FWVER_BUF_LEN];
+        struct mkhi_msg *req;
+        struct mkhi_fw_ver *fwver;
+        int bytes_recv, ret, i;
+
+        memset(buf, 0, sizeof(buf));
+
+        req = (struct mkhi_msg *)buf;
+        req->hdr.group_id = MKHI_GEN_GROUP_ID;
+        req->hdr.command = MKHI_GEN_GET_FW_VERSION_CMD;
+
+        ret = __mei_cl_send(cldev->cl, buf, sizeof(struct mkhi_msg_hdr),
+                            MEI_CL_IO_TX_BLOCKING);
+        if (ret < 0) {
+                dev_err(&cldev->dev, "Could not send ReqFWVersion cmd\n");
+                return ret;
+        }
+
+        ret = 0;
+        bytes_recv = __mei_cl_recv(cldev->cl, buf, sizeof(buf), 0,
+                                   MKHI_RCV_TIMEOUT);
+        if (bytes_recv < MKHI_FWVER_LEN(1)) {
+                /*
+                 * Should be at least one version block,
+                 * error out if nothing found
+                 */
+                dev_err(&cldev->dev, "Could not read FW version\n");
+                return -EIO;
+        }
+
+        fwver = (struct mkhi_fw_ver *)req->data;
+        memset(cldev->bus->fw_ver, 0, sizeof(cldev->bus->fw_ver));
+        for (i = 0; i < MEI_MAX_FW_VER_BLOCKS; i++) {
+                if (bytes_recv < MKHI_FWVER_LEN(i + 1))
+                        break;
+                dev_dbg(&cldev->dev, "FW version%d %d:%d.%d.%d.%d\n",
+                        i, fwver->ver[i].platform,
+                        fwver->ver[i].major, fwver->ver[i].minor,
+                        fwver->ver[i].hotfix, fwver->ver[i].buildno);
+
+                cldev->bus->fw_ver[i].platform = fwver->ver[i].platform;
+                cldev->bus->fw_ver[i].major = fwver->ver[i].major;
+                cldev->bus->fw_ver[i].minor = fwver->ver[i].minor;
+                cldev->bus->fw_ver[i].hotfix = fwver->ver[i].hotfix;
+                cldev->bus->fw_ver[i].buildno = fwver->ver[i].buildno;
+        }
+
+        return ret;
+}
+
 static void mei_mkhi_fix(struct mei_cl_device *cldev)
 {
         int ret;
 
-        if (!cldev->bus->hbm_f_os_supported)
-                return;
-
         ret = mei_cldev_enable(cldev);
         if (ret)
                 return;
 
-        ret = mei_osver(cldev);
+        ret = mei_fwver(cldev);
         if (ret < 0)
-                dev_err(&cldev->dev, "OS version command failed %d\n", ret);
+                dev_err(&cldev->dev, "FW version command failed %d\n", ret);
 
+        if (cldev->bus->hbm_f_os_supported) {
+                ret = mei_osver(cldev);
+                if (ret < 0)
+                        dev_err(&cldev->dev, "OS version command failed %d\n",
+                                ret);
+        }
         mei_cldev_disable(cldev);
 }
 
diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
index 7465f17e1559..f690918f7817 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -1,7 +1,7 @@
 /*
  *
  * Intel Management Engine Interface (Intel MEI) Linux driver
- * Copyright (c) 2003-2012, Intel Corporation.
+ * Copyright (c) 2003-2018, Intel Corporation.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -812,11 +812,39 @@ static ssize_t tx_queue_limit_store(struct device *device,
 }
 static DEVICE_ATTR_RW(tx_queue_limit);
 
+/**
+ * fw_ver_show - display ME FW version
+ *
+ * @device: device pointer
+ * @attr: attribute pointer
+ * @buf:  char out buffer
+ *
+ * Return: number of the bytes printed into buf or error
+ */
+static ssize_t fw_ver_show(struct device *device,
+                           struct device_attribute *attr, char *buf)
+{
+        struct mei_device *dev = dev_get_drvdata(device);
+        struct mei_fw_version *ver;
+        ssize_t cnt = 0;
+        int i;
+
+        ver = dev->fw_ver;
+
+        for (i = 0; i < MEI_MAX_FW_VER_BLOCKS; i++)
+                cnt += scnprintf(buf + cnt, PAGE_SIZE - cnt, "%u:%u.%u.%u.%u\n",
+                                 ver[i].platform, ver[i].major, ver[i].minor,
+                                 ver[i].hotfix, ver[i].buildno);
+        return cnt;
+}
+static DEVICE_ATTR_RO(fw_ver);
+
 static struct attribute *mei_attrs[] = {
         &dev_attr_fw_status.attr,
         &dev_attr_hbm_ver.attr,
         &dev_attr_hbm_ver_drv.attr,
         &dev_attr_tx_queue_limit.attr,
+        &dev_attr_fw_ver.attr,
         NULL
 };
 ATTRIBUTE_GROUPS(mei);
diff --git a/drivers/misc/mei/mei_dev.h b/drivers/misc/mei/mei_dev.h
index 4058ab5ad2d8..d522585b71b7 100644
--- a/drivers/misc/mei/mei_dev.h
+++ b/drivers/misc/mei/mei_dev.h
@@ -1,7 +1,7 @@
 /*
  *
  * Intel Management Engine Interface (Intel MEI) Linux driver
- * Copyright (c) 2003-2012, Intel Corporation.
+ * Copyright (c) 2003-2018, Intel Corporation.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -355,6 +355,25 @@ enum mei_pg_state {
 const char *mei_pg_state_str(enum mei_pg_state state);
 
 /**
+ * struct mei_fw_version - MEI FW version struct
+ *
+ * @platform: platform identifier
+ * @major: major version field
+ * @minor: minor version field
+ * @buildno: build number version field
+ * @hotfix: hotfix number version field
+ */
+struct mei_fw_version {
+        u8 platform;
+        u8 major;
+        u16 minor;
+        u16 buildno;
+        u16 hotfix;
+};
+
+#define MEI_MAX_FW_VER_BLOCKS 3
+
+/**
  * struct mei_device -  MEI private device struct
  *
  * @dev         : device on a bus
@@ -402,6 +421,8 @@ const char *mei_pg_state_str(enum mei_pg_state state);
  * @hbm_f_ie_supported  : hbm feature immediate reply to enum request
  * @hbm_f_os_supported  : hbm feature support OS ver message
  *
+ * @fw_ver : FW versions
+ *
  * @me_clients_rwsem: rw lock over me_clients list
  * @me_clients  : list of FW clients
  * @me_clients_map : FW clients bit map
@@ -478,6 +499,8 @@ struct mei_device {
         unsigned int hbm_f_ie_supported:1;
         unsigned int hbm_f_os_supported:1;
 
+        struct mei_fw_version fw_ver[MEI_MAX_FW_VER_BLOCKS];
+
         struct rw_semaphore me_clients_rwsem;
         struct list_head me_clients;
         DECLARE_BITMAP(me_clients_map, MEI_CLIENTS_MAX);